(()=>{
    let a:number = 0;
    let i:number = 0;
    let arr:number[] = [1,2,1,21,21,54,12,0,1,2]
    let arr1:number[] = [];

    // let a1 = new Set(arr);
    let a1 = arr.sort((a,b)=>a-b)
    let a2 = new Set(a1);
    console.log(a2)
})()